hollardops vs. Metacanthina Leonaspis vs. Kettneraspis

a las buenas noches
la clasificación de los trilos marroquies es un pollo de cuidado...ando dando tumbos de lado a lado. En el Fossil forum he encontrado lo siguiente y creo que puede ser util

Hollardops and Metacanthina (Order Phacopida - Family Asteropyginae) have been playing a fun game of musical chairs. Hollardops was formally Metacanthina. Metacanthina was previously referred to as Asteropyge or Kayserops and along the way, Philipsmithiana never quite made it as a new name before Hollardops officially occupied the name for that genus. Attached are figures of Hollardops and a link to a gallery of Metacanthina for comparison. Suffice it to say there are a myriad of species and these two particular examples represent only the most common elements of the group as a whole.
Por lo que se ve, prevalece Hollardops sobre Metacanthina...no?

Sobre Leonaspis/ Kettneraspis
I've been looking at your photographs and I think that the Leonaspis that you display are Kettneraspis. There seem to be some difficulties concerning Leonaspis. Adrain & Ramskold (1997) consider Leonaspis as a polyphyletic group. It is divided into Leonaspis, Kettneraspis and Adrain & Ramskold have added Edgecombeaspis in 1997 which is derived from Kettneraspis. Concerning differences between Leonaspis and Kettneraspis, the pygidial spines are a way to distinguish both genera. Leonaspis has 4 small spines between 2 long spines, while Kettneraspis has 2 small spines between 2 long spines.
Combined with my work on several cranidia and a cephalothorax of a Leonaspis-like species wearing an occipital spine, there are some comments. There are "Leonaspis" from Morocco that wear a spine on the occipital lobe but these seem to be much more robust and larger than what we see in our region. I have seen quite a few and mostly they appeared to be Kettneraspis. I am not sure about my own specimens because I have no pygidium saved with them. I do have a cephalothorax that is with certainty a Leonaspis or Kettneraspis. There are differences in the cranidium as well between both genera and they are described in the paper by Adrain & Ramskold, which I am trying to get somewhere. There is also a paper by Ramskold & Chatterton in which the polyphyletic group of Leonaspis is revised but I do not know about its contents and if it is earlier or later than the Adrain & Ramskold paper.
Está claro que son especies diferentes. Kettneraspis se suele representar sin embargo todavía acompañado de Leonaspis entre parentesis. Les diferencia sobre todo las espinas marginales del pigidio.
Supongo que para Kettneraspis la nomenclatura oficial es la de Adrain & Ramskold 1997. La del Leonaspis no la encuentro...
En fin...alguien tiene algún dato actual sobre estas especies?

Buenas, sobre Hollardops y Metacanthina, son la misma especie. Aveces lo ponen como Metacanthina y aveces como Hollardops. Yo personalmente siempre les digo Hollardops.
Sobre los Leonaspis y Kettneraspis, parece ser dos especies diferentes, aunque yo tengo las dos especies y nunca les he visto una diferencia significativa. Les mirare las espinas del pigido aver xD. Antes pensaba que eran la misma especie.
Sobre informacion del leonaspis mirare aver si veo algo porque no tengo nada.
Saludos.

gracias Heteroceras
creia que sería más fácil. Voy a ver si mi edición del Treatise dice algo más, aunque ya tiene unos añitos...